Stamping–forging hybrid forming of double layer cup with different wall thicknesses

摘要

A double layer cup with different wall thicknesses was studied. The wall thickness of the innerncylinder was 4 mm and that of the other sections was 2 mm. According to this characteristic, thenouter cylinder was first formed by forward drawing, then the inner cylinder was formed bynpowerful backward drawing and, finally, the inner cylinder was thickened by upsetting to meet thenrequirements. The finite element simulation software Marc was used to analyse the effect of shapenand size of blank holder, specific velocity and fillet on the forming. The results show that a blanknholder with filleting can effectively promote the material flow from the wall of the outer cylinder tonthat of the inner cylinder during the powerful backward drawing, that the minimum and maximumnvalues of the wall thickness of the inner cylinder increase with increasing specific velocity and thatnthe corner with filleting can guide the material flow effectively to avoid folding during thenthickening forming.